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[82.69.66.36]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3a4f009fbf7sm16005839f8f.83.2025.06.02.14.08.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Jun 2025 14:08:57 -0700 (PDT) Date: Mon, 2 Jun 2025 22:08:55 +0100 From: David Laight To: =?UTF-8?B?Q2zDqW1lbnQgTMOpZ2Vy?= Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , "Maciej W . Rozycki" Subject: Re: [PATCH v2 0/3] riscv: misaligned: fix misaligned accesses handling in put/get_user() Message-ID: <20250602220855.519e23e5@pumpkin> In-Reply-To: <20250602193918.868962-1-cleger@rivosinc.com> References: <20250602193918.868962-1-cleger@rivosinc.com> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; arm-unknown-linux-gnueabihf) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Mon, 2 Jun 2025 21:39:13 +0200 Cl=C3=A9ment L=C3=A9ger wrote: ... > The second solution was the one chosen as there are too many callsites to > put/get_user() that could potentially do misaligned accesses. We tried > two approaches for that, either split access in two aligned accesses > (and do RMW for put_user()) You can't do RMW because it is visible to other threads. David